[Analysis of immune response to Helicobacter pylori--identification of the protein recognized by anti-Helicobacter pylori antibodies from sera of patients with gastroduodenal diseases].

HP-specific antibodies were measured in each collected fraction obtained from gel-filtrated separation method with selected patients sera by enzyme-linked immunosorbent assay (ELISA). Most of the fractions reacted with the patients sera also responded to HP urease-specific monoclonal antibodies. In addition, the fractions which showed urease activity strongly correlated with the HP antibody positive ones. Also, we could not detect any cross-reactivity to ureases of other species. Moreover, most patient sera strongly responded to the purified HP urease B subunit separated with SDS/PAGE by western blotting analysis. These findings suggest that the major target for HP-specific antibodies appears to be HP-urease, in particular around 68kd large molecule, urease B subunit and such urease-specific antibodies are isolate-species specific.